Apparatus for promoting complete combustion

ABSTRACT

Apparatus for insuring that combustion within a combustion chamber of an apparatus such as a heater, boiler, furnace, and the like, includes arranging the fuel, air and ignition means in a combustion chamber such that combustion takes place in the vicinity of a heat-conducting and heat-equalizing device in order to insure an even temperature zone at the combustion space and to minimize the danger of carbonizing or coking. The heat-conducting and heat-equalizing device comprises preferably a hollow body made of a material providing good heat conduction and heatequalizing characteristics, such as a mass of a metal material having a capillary action on liquid contacted thereby. The hollow body is advantageously filled with a liquid such as sodium and the material of the metal body, for example, a spun copper or a braid metal material is such that by capillary action the heat is distributed by the liquid uniformly over the entire surface of the body. The heat-conducting and heat-equalizing body is arranged directly in a space where the major portion of the combustion is to take place.

United States Patent [72] Inventor Siegfried Koiink Zell/Neckar, Germany[21] Appl. No. 838,737 [22] Filed July 3, 1969 [45] Patented July 13,1971 [73] Assignee J. Eberspacher Esslingen am Neckar, Germany [32]Priority Oct. 18, 1968 [33] Germany [31] P18038153 [54] APPARATUS FORPROMOTING COMPLETE COMBUSTION 3 Claims, 4 Drawing Figs.

[52] US. Cl 431/263, 431/350 [51] Int. Cl. F23d 13/24 [50] FieldofSearch 431/263, 347, 350, 353, 338; 110/97 [56] References CitedUNlTED STATES PATENTS 1,264,448 4/1918 Smith 431/347 2,072,731 3/1937Crosby 431/263 2,465,092 3/1949 Harkness et al. 431/263 2,857,96110/1958 Brown et al 431/353 X FOREIGN PATENTS 904,901 9/ l 962 GreatBritain 431/353 165,554 3/1950 Austria 431/338 Primary ExaminerCarrollB. Dority, Jr. Au0meyMcGlew and Toren ABSTRACT: Apparatus for insuringthat combustion within a combustion chamber of an apparatus such as aheater, boiler, furnace, and the like, includes arranging the fuel, airand ignition means in a combustion chamber such that combustion takesplace in the vicinity of a heat-conducting and heatequalizing device inorder to insure an even temperature zone at the combustion space and tominimize the danger of carbonizing or coking. The heat-conducting andheat-equalizing device comprises preferably a hollow body made of amaterial providing good heat conduction and heat-equalizingcharacteristics, such as a mass of a metal material having a capillaryaction on liquid contacted thereby. The hollow body is advantageouslyfilled with a liquid such as sodium and the material of the metal body,for example, a spun copper or a braid metal material is such that bycapillary action the heat is distributed by the liquid uniformly overthe entire surface of the body. The heat-conducting and heat-equalizingbody is arranged directly in a space where the major portion of thecombustion is to take place.

PATENTED JUL 1 3 IQYI 3 592 5 T SHEET 1 or 2 lNVENTOR Siegfried KofinkATTORNEYS.

PATENTED JUL 1 3 ISYI SHEET 2 OF 2 FIG.3

FEGA

/NVENTOR Siegfried Kofink @614 ATTORNEYS.

APPARATUS FOR PROMOTING COMPLETE COMBUSTION SUMMARY OF-THE INVENTIONThis invention relates in general to apparatus for improving combustion,and in particular, to a new and useful device such as a heater, or thelike, having a combustion chamber with means for admitting fuel and airinto a combustion space for combustion in the vicinity of a body of ahighly conductive heat-equalizing material to promote a heat-equalizingzone of substantially constant temperature within the combustionchamber.

The present invention is particularly concerned with the provision of acombustion chamber having a heat-equalizing means therein arranged tolessen the tendency toward coking or carbonizing of the fuel during thecombustion process with a view to obtaining preferably a bluecombustion, that is, a combustion of the fuel which, will proceed to theextent that there will be very little or any residue remaining upon thecompletion of the combustion.

It is known that coking will occur in combustion chamber devicesutilizing pressure atomization burners, or similar fuel injectiondevices, for example, in space heaters for automobiles, that a cokingwill occur due to poor or irregular combustion. During the mixing of theinjected fuel and the combustion and upon combustion and ejection of thehot combustion gases, different temperatures occur in the combustionchamber particularly at the walls thereof. Because of these differencesof temperature there is always a temperature at which some portion ofthe fuel mixture will not burn completely but will deposit as a cokingproduct on the walls. Such deposition products, as for example hardasphalt will deposit at various locations on the combustion apparatusand hence the progress of the combustion will be considerably disturbed.This disturbed combustion will also cause smoke emission, or smoldering,in the-combustion chamber and this will contribute to pollution of theairrThis has particular dis advantages, for example in respect to spaceheating systems in motor vehicles. Of course, when these systems arebadly coked or carbonized, they will require servicing to remove thedepositions for example, by scrapping. The time required for suchscrapping is balanced by the-fact that the overall efficiency of thecombustion chamber will decrease to an extent that it cannot be operatedany longer.

A primary cause for the coking or carbonizing is the differences oftemperature which exist along the length of a combustion chamber andtherefore attempts have been made to achieve an improvement of thecondition by the use of suitable inserts. It has been tried for example,to bring about an improvement by the installation of copper conductingelements but the copper has so low an oxidation temperature that theseinserts burn up in a short time. Other materials which seem suitablewere eithertoo expensive or their conductivity is too low.

In accordance with the present invention, a combustion chamber having ameans for supplying combustion air and fuel into a zone in which thefuel and air is to be ignited, and which may include, for example, meansfor deflecting and guiding the flame produced, there isprovided anarrangement by which coking is prevented and blue combustion of theliquid fuel is achieved. To achieve this a-heat tube is arranged in theregion of the fuel mixture processing zone and-the combustion zone orcombustion space. Such'aheat tube comprises a heatconducting andheat-equalizing mass which is preferably in the form of a tubecomprisinga metallic hollow body made of a material having a masscapillary action on liquid and good conductivity, for example, spuncopper or a braid material. The interior of the body is filled with atleast a small quantity of a liquid such asa liquid sodium: This liquidevaporates upon being heated, and by the capillary. action of thematerial forming the hollow body and distributes the heat uniformly overthe entire surface of the heat tube so that the temperature gradientthroughout the burning space and the combustion chamber is substantiallyzero. By the arrangement of the heat mass or heat tube in accordancewith the invention the combustion chamber space can be maintained at asubstantially uniform temperature along its entire extent so that therewill be little or no likelihood of undesired coking or carbonizingtaking place. The construction is such that there will usually occur asudden heatjump in the combustion chamber of from 50to 700 C. from theair supply and fuel mixture supply conduits. This heat jump will dependon the design of the entire combustion chamber arrangement, however. Byemploying a heat tube made of a spun copper mass having a capillaryaction on the liquid, it is possible to achieve substantially 10,000times the thermal conductivity of ordinary copper.

In accordance with the embodiment of the invention the heat mass isdesigned as a heat tube in the form of a ring or space cylinder. Thiscylinder advantageously includes, on the heat admission side, means forincreasing the heat transfer area such as extensions or ribs. Theapparatus may be incorporated in a space heating burner for examplewherein the tube has an opening to accommodate a spark plug forproviding central ignition to a fuel and air mixture which is admittedaxially. In one form the invention may be incorporated in a resonantburner in which the heat tube is located adjacent the supply conduitsfor air and fuel in back of the means for igniting the mixture.

In another embodiment the heat-conducting and heatequalizing mass ismaintained in a central location, for example on a pot burner in whichit will extend axially upwardly therefrom in the direction of flamepropagation.

Accordingly, it is an object of the invention to provide an improvedcombustion device which includes a mass of material having good heatconducting and heat equalizing capabilities which is arranged in thevicinity of the combustion space and provides a means for maintaining auniform temperature in this space in order to promote completecombustion of the fuel.

7 A further object of the invention is to provide a combustion chamberwhich includes a tube of a material such as a spun copper or braidhaving a capillary action characteristic and which includes a cavitywhich is filled with a liquid such as sodium which is adapted to bemoved by the capillary action of the material forming the mass in orderto provide a temperature equalization throughout the length of the massin the combustion chamber.

A further object of the invention is to provide a device such as a potburner which includes a mass of a material in the pot adapted to contactthe fuel therein and extending upwardly in the direction of flamepropagation and providing a heat-conducting and heat-equalizing mass forinsuring a uniform temperature in the combustion zone of the burner.

A further object of the invention is to provide the combustion devicehaving means for maintaining a combustion zone or temperatureequalization and which is simple in design, rugged in construction, andeconomical to manufacture.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which there are illustrated and describedpreferred embodimentsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. 1 is a partial axial sectional view of an automobile space heaterhaving a combustion chamber constructed in accordance with theinvention;

FIG. 2 is a view similar to FIG. I of a resonant burner;

FIG. 3 is a view similar to FIG. 1 ofa household pot burner for homeheating units; and

FIG. 4 is a view similar to FIG. 1 of an atomizing burner for a boileror similar device.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to thedrawings in particular, the invention embodied therein in FIG. 1comprises an automobile space heater generally designated 50 whichincludes a housing 52 defining a combustion chamber 1 having a radialextension 54 defining a chamber 4 for a spark plug 6. Fuel is admittedthrough a conduit 5 into the antechamber 4 for combustion in thecombustion chamber or space 1. Combustion air is admitted through acentral tubular member 7 to the combustion chamber zone defined withinthe chamber 1. Discharge of the heated high-temperature gases is througha flame nozzle section 8 of the housing 52.

In accordance with the invention the combustion space 1 is provided witha heat-conducting and heat-equalizing device in the form of a hollowtube 2 made ofa metallic material such as spun copper or braid. Thematerial of the tube 2 is advantageously such that it effects acapillary action on liquid in contact therewith. lt is effective to drawa liquid such as liquid sodium 56, which is partially filled into theinterior thereof, throughout the length of the tube in order to providea temperature equalization zone within the combustion chamber 1. Thetubular mass 2 therefore provides a means for distributing the heatuniformly over the entire surface of the tube in the combustion chamberspace 1 to insure that there is no area of temperature variation in thisspace which would prevent the good burning of the fuel admitted thereto.The distribution of the sodium throughout the mass of the tube 2 bycapillary action is such that the temperature gradient may be reduced tosubstantially zero. in the embodiment of FIG. I, the tube 2 is providedwith an opening 2a to permit access of the spark plug 6.

In the embodiment indicated in FIG. 2, there is provided a resonant oroscillating burner generally designated 58 which includes an axiallyelongated combustion zone or space 9 and is provided with an ignitionantechamber for a spark plug 6'. In this construction a temperatureequalizing mass 2 in the form of a tubular member is positioned in theprincipal combustion zone 11 adjacent to and to the rear of the sparkplug 6. The tubular mass 2' is arranged directly adjacent and in heatconduction with a flame tube 10. Combustion air is supplied through acombustion inlet connection 12 and fuel is supplied through a nozzle 13,into the combustion space 11.

In the embodiment indicated in FIG. 3, there is shown a burner ofa typewhich may be employed in a boiler or similar heating apparatus and whichincludes a burner pot 14 having an evaporator disc 15 spaced from thebottom wall of the pot and which is supplied with a fuel through aninlet 13. The required combustion air is directed in through an inlet 16which is directed through a perforated air supply pot ring 17. A flamering 18 is mounted on one end of the combustion air supply ring 17 andit carries a flame holder 19. In accordance with the feature of thisembodiment a heat-conducting and heat-equalizing mass 20 in the form ofa tube 20 is arranged in conductive connection between the flame holder19 and the fuel-evaporating disc 15. A plurality of extending ribs 21provide increased conductive surfaces for the tube 20. The tube 20 mayadvantageously be filled with a liquid sodium 60 for example as in theembodiment of FIG. 1.

In the embodiment shown in FIG. 4, there is shown a conventional boilerfurnace portion 62 having a flue 22. An atomizer burner 23 is positionedin a wall of the boiler and extends into the furnace chamber. Theatomizer burner 23 includes a central fuel delivery conduit 26terminating in an atomizer nozzle 24 which directs the fuel in the formof a spray 64 into the combustion zone. An air diffuser piece or airnozzle 27 is arranged atone end of the atomizer burning housing assemblyfor aiding in the directing of the air into association with the fuelspray 64. Combustion air flows through the atomizer burner housing 23 tothe combustion space at the interior of the furnace 62. In thisembodiment a heat ring tube 2" is arranged directly adjacent the burnernozzle assembly and it is made of a mass providing a good heatconduction and good heat equalization throughout an axial length in thefurnace 62 corresponding to the combustion length.

lclaim:

1. A combustion device comprising wall means defining a combustionchamber, means for directing fuel and combustion air into saidcombustion chamber and for igniting the fuel and combustion air thereinto provide combustion proceeding along a combustion zone, and a heatconductive mass arranged in the combustion zone and being of a materialto provide a temperature equalization throughout said combustion zone,said heat conductive mass comprising a hollow metallic mass having atleast the interior thereof of a material having a capillary action, anda liquid in said mass capable of evaporating when subjected to heat tobe drawn by capillary action throughout the length of said mass toequalize the temperature thereof.

2. A combustion device, as set forth in claim 1, wherein said liquid insaid mass being a liquid sodium.

3. A combustion device, as set forth in claim 1, wherein said wall meanscomprises an axial discharge for the combustion flame, an axial inletopposite to said discharge for combustion air, an antechamber having aspark plug therein, means for admitting a liquid fuel into saidantechamber, said antechamber being connected to said combustion chamberfor mixing the fuel with the combustion air being moved therethrough andfor ignition of the mixture by said spark plug, said hollow metallicmass comprising a hollow ring of a conductive metallic material, andsaid ring having an opening therethrough for communicating saidantechamber to said combustion chamber.

2. A combustion device, as set forth in claim 1, wherein said liquid insaid mass being a liquid sodium.
 3. A combustion device, as set forth inclaim 1, wherein said wall means comprises an axial discharge for thecombustion flame, an axial inlet opposite to said discharge forcombustion air, an antechamber having a spark plug therein, means foradmitting a liquid fuel into said antechamber, said antechamber beingconnected to said combustion chamber for mixing the fuel with thecombustion air being moved therethrough and for ignition of the mixtureby said spark plug, said hollow metallic mass comprising a hollow ringof a conductive metallic material, and said ring having an openingtherethrough for communicating said antechamber to said combustionchamber.